Journal Issue Information

| سال:0 | دوره: | شماره:

Archive

Year

Volume(Issue)

Issues

مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
Issue Info: 
  • Year: 

    2014
  • Volume: 

    3
  • Issue: 

    2
  • Start Page: 

    101
  • End Page: 

    113
Measures: 
  • Citations: 

    0
  • Views: 

    15156
  • Downloads: 

    10557
Keywords: 
Abstract: 

Hemoglobin is a porphyrin containing protein with an a2b2 tetrameric structure and like other porphyrin compounds shows spectral behavior of species specific characteristics. Researchers tend to relate bands in the hemoglobin spectra to certain structural and/or functional features. Given the fact that hemoglobin is the main oxygen carrier in animals functioning through the Oxy«Deoxy equilibrium, the determination of oxy and deoxy conformations of hemoglobins of different animals may shed light on their oxygen binding properties. Absorption spectra at 280 and 373nm have been widely used to quantitate the formation of hemoglobin deoxy conformation. In the present work, however, we used an optical density ratio of OD373/OD280 as an index for deoxy formation. This ratio was determined for Barbus sharpeyi and human hemoglobins at different SDS concentrations, pH levels and temperatures to compare them from a structure-function point of view. Our data showed that under low concentrations of SDS (<2mM) Barbus sharpeyi hemoglobin folds in a tri-state pattern while human hemoglobin folds through a two-state phenomenon. This finding indicates that in contrast to those of other non aquatic animals, the hemoglobin of Barbus sharpeyi has a loosely folded tetrameric structure with remarkably more oxygen affinity.

Yearly Impact:  

View 15156

Download 10557 Citation 0 Refrence 0
Issue Info: 
  • Year: 

    2014
  • Volume: 

    3
  • Issue: 

    2
  • Start Page: 

    115
  • End Page: 

    127
Measures: 
  • Citations: 

    0
  • Views: 

    16100
  • Downloads: 

    9469
Keywords: 
Abstract: 

Clostridium botulinum type A (BoNT/A) produces a neurotoxin recently found to be useful as an injectable drug for the treatment of abnormal muscle contractions. The catalytic domain of this toxin which is responsible for the main toxin activity is a zinc metalloprotease that inhibits the release of neurotransmitter mediators in neuromuscular junctions. A cell penetrating cationic peptide, Tat, which is a truncated N-terminal part of the Tat protein from human immunodeficiency virus, can help the toxin penetrate the skin uninvasively. This study aimed at an in silico analyses of the Tat-BoNT/A (1-448) fusion protein structure. A genomic construct was designed and optimized based on E.coli codon usage. The structure of mRNA as well as the properties of hypothetical chimeric protein was then analyzed by bioinformatic tools. Afterwards, the secondary and tertiary structures of the fusion protein were predicted by GOR4 and I-TASSER online web servers. The interaction with synaptosomal associated protein 25kDa (SNAP-25) was also analyzed as a natural substrate for the toxin. Based on the studied secondary and tertiary structures of the protein, the selected order of fusion proteins provides the natural activity of each peptide. Energy calculating data show that the acquired thermodynamic ensemble related to the mRNA structure was-1473.2 kJ/mol (-352.10 kcal/mol) and both total protein energy (Etotal) and shape related energy (Eshape) were calculated as -2294.2kJ/mol (-548.32 kcal/mol). The stability index of TAT-BoNT/A was computed to be 27.22 which has an acceptable stability as compared to that of native BoNT/A (22.39).

Yearly Impact:  

View 16100

Download 9469 Citation 0 Refrence 0
Issue Info: 
  • Year: 

    2014
  • Volume: 

    3
  • Issue: 

    2
  • Start Page: 

    129
  • End Page: 

    139
Measures: 
  • Citations: 

    0
  • Views: 

    16145
  • Downloads: 

    4182
Keywords: 
Abstract: 

The present study was conducted to find the effect of three heavy metals, Ag, Hg and Pb on the expression level of a gene encoding plasma membrane H+-ATPase in Aeluropus littoralis. The experiment was laid out in a completely random design with three replications. Theexpression of the main gene was normalized to the expression of the housekeeping gene actin. Two 259 and 187 bp fragments were amplified from plasma membrane H+-ATPase and actin genes using specific primers in polymerase chain reactions. The results indicated that higher concentrations of all three heavy metals declined the expression of plasma membrane H+-ATPase gene, whereas low concentrations changed the level of its transcript differently. A significant linear correlation was found between Ag concentrations of Aeluropus littoralis shoots and its external level; however, for Hg and Pb no correlations were observed. Root weight decreased when plants were grown at both concentrations of Ag and Hg but increased at both concentrations of Pb and NaCl. Maximum root weight was observed under lower levels of Pb, while maximum shoot weight was observed under lower levels of Hg. The greatest plant weight was obtained at low concentrations of Hg and Pb. Taken together these results show the regulation of plasma membrane H+-ATPase gene by heavy metals suggesting that Aeluropus littoralis can be regarded as a Phytoremediation accumulator of soils polluted with heavy metals.

Yearly Impact:  

View 16145

Download 4182 Citation 0 Refrence 0
Issue Info: 
  • Year: 

    2014
  • Volume: 

    3
  • Issue: 

    2
  • Start Page: 

    141
  • End Page: 

    147
Measures: 
  • Citations: 

    0
  • Views: 

    12926
  • Downloads: 

    5027
Abstract: 

The present study aimed at investigating the beneficial effects of co-administering granulocyte colony–stimulating factor (G-CSF) and stem cell factor (SCF) in a model of chronic liver injury induced by thioacetamide (TAA). Biochemical and histopathology- cal examinations were performed on serum and liver specimens. At the end of the treatment period, the rats were anesthetized with ether, serum was collected and sections of randomly selected fixed liver specimens from each group were embedded in paraffin and processed for light microscopy by staining individual sections with hematoxylin-eosin (HE) stain. Administration of a combination of G-CSF+SCF was carried out two weeks after the TAA treatment. Livers of rats treated with TAA alone exhibited damage, which was significantly less in the group treated with the combination of SCF and G-CSF. Albumin level was 2.35 (g/dl) in the G-CSF+SCF and 1.03 in the TAA-alone group. These differences were statistically significant (P<0.05). Also, in the G-CSF+SCF and TAA group the total protein means (7.16 versus 3.57 mg/dl, respective-ly) were higher than those of the TAA-alone group, and the differences were statistically significant (P<0.05). In the G-CSF+SCF and TAA group the total bilirubin content mean (0.15 versus 0.14 mg/dl, respectively) this difference was not statistically significant (P>0.05).

Yearly Impact:  

View 12926

Download 5027 Citation 0 Refrence 0
Issue Info: 
  • Year: 

    2014
  • Volume: 

    3
  • Issue: 

    2
  • Start Page: 

    75
  • End Page: 

    84
Measures: 
  • Citations: 

    0
  • Views: 

    11242
  • Downloads: 

    5130
Keywords: 
Abstract: 

Nitrate is one of the major sources of nitrogen for the growth of plants. It is taken up by plant roots and transported to the leaves where it is reduced to nitrite in the. The main objective of this research was to investigate stimulatory effects of sodium nitrate, potassium nitrate, ammonia and urea on the production/generation of the nitrate reductase mRNA in Triticum aestivum plants. The plants were grown in standard nutrient solution for 21 days and then starved in a media without nitrate for seven days. Starved plants were stimulated with various concentrations of sodium nitrate, potassium nitrate, ammonia and urea, and the expression of nitrate reductase mRNA was analyzed by real-time PCR. Our results indicated that starvation caused significant decrease in the production of nitrate reductase mRNA in the plant leaf. Sodium and potassium nitrate were capable of restoring the production of nitrate mRNA in a dose-dependent manner, since 50 mM of each produced the highest level of the mRNA. The stimulatory effect of potassium nitrate was higher than sodium nitrate, while ammonia and urea did not show such activity. At low concentrations, sodium nitrate and potassium nitrate caused significant increase in the nitrate/nitrite mRNA production, whereas high concentrations of these salts suppressed the expression of this gene considerably.

Yearly Impact:  

View 11242

Download 5130 Citation 0 Refrence 0
Issue Info: 
  • Year: 

    2014
  • Volume: 

    3
  • Issue: 

    2
  • Start Page: 

    85
  • End Page: 

    100
Measures: 
  • Citations: 

    0
  • Views: 

    15027
  • Downloads: 

    4967
Abstract: 

Lactoferrin (Lf) is an iron-binding multi-functional glycoprotein which has numerous physiological functions such as iron transportation, anti-microbial activity and immune response. In this study, different in silico approaches were exploited to investigate Lf protein properties in a number of mammalian species. Results showed that the iron-binding site, DNA and RNA-binding sites, signal peptides and transferrin motifs in the Lf structure were highly conserved. Examined sequences showed three conserved motifs which were repeated twice in the Lf structure, demonstrating ancient duplication events in its gene. Also, results suggest that the functional domains in mammalian Lf proteins are Zinc finger, Tubulin/FtsZ, GTPase, a/b hydrolase and Zinc knuckle. The potential site for nucleic acid binding and the major DNA and RNAbinding sites in this protein were found in the lactoferricin (Lfc) fragment. Due to its high positive charge, Lf is able to bind a large number of compounds. Our analysis also revealed that the interactions between Lf and ITLN1, LYZ, CSN2, and CD14 proteins played an important role in the protective activities of Lf. Analysis for the prediction of secondary structures indicated that high amounts of a-helix, b-strand and b-sheet were present in Lf. The high degree of conservation among mammalian Lf proteins indicates that there is a close relationship between these proteins, reflecting their important role.

Yearly Impact:  

View 15027

Download 4967 Citation 0 Refrence 0

Advertising

مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID